Choroidal neovascularization (CNV) is a disease in which new blood vessels develop from the choroid in the macula of the ocular fundus, and appears in angioid streaks of retina, pathological myopia, ophthalmic histoplasmosis, posttraumatic choroidal rupture and the like, besides in age-related macular degeneration (AMD).
Since new choroidal blood vessels are fragile, the blood components exude, to cause retinal edema and accumulation of subretinal fluid. Further, as a result of hemorrhage due to rupture of fragile new blood vessels, the failure that influences on decline in visual acuity progresses acceleratively (Non-patent document 1).
For example, for choroidal neovascularization in age-related macular degeneration, angiogenesis inhibitors such as an anti-VEGF drug that inhibit neovascularization have been used (Non-patent document 2).
AMD is a disease in which the macula of the retina becomes damaged by a factor such as aging, to result in visual loss. In advanced AMD, objects or linear objects appear distorted (metamorphopsia), and color cannot be recognized, and patients with advanced AMD can become sensitive to light, and become largely influenced in their Quality of Life. More advanced AMD can result in partial defect of visual field (central scotoma, etc.), and can lead to blindness (Non-patent document 3).
AMD is roughly classified into Wet AMD (exudative AMD), and Dry AMD (atrophic AMD) according to the characteristic clinical state. Wet AMD is a type characterized by abnormal neovascularization and rupture thereof. In Wet AMD, blood vessels newly develop from the choroid under retinal pigment epithelium (RPE cells), and blood components exude from these fragile blood vessels to cause retinal edema and accumulation of subretinal fluid. Further, as a result of hemorrhage due to rupture of fragile blood vessels, the failure that influences on decline in visual acuity progresses acceleratively (Non-patent document 1).
As a therapeutic method of AMD, angiogenesis inhibitors such as an anti-VEGF (vascular endothelial growth factor) drug that inhibit neovascularization have been used for Wet AMD (Non-patent document 2).
On the other hand, Dry AMD is a disease that is diagnosed based on the criteria for visual acuity, funduscopic findings, image findings, exception, severity classification and the like (Non-patent document 4). Irregularity in visual cells caused by a structure called drusen is considered as one causal factor (Non-patent document 5). There is a report that some Dry AMD transit to Wet AMD.